Racial/Ethnic Differences in Psychiatric and Medical Diagnoses Among Autistic Adults.

Background: Racial/ethnic disparities in access to diagnostic services are pervasive for autistic children. However, a few studies have examined racial/ethnic health disparities among autistic adults, who commonly experience higher rates of health conditions than non-autistic adults. We aimed at examining the intersection of autism and race/ethnicity in association with psychiatric and medical diagnoses.

Methods: The study population included adult members of Kaiser Permanente Northern California enrolled from 2008 to 2012. We ascertained 1507 adults who had an autism diagnosis documented in their electronic medical records. We sampled a matched control group of adults without an autism diagnosis (N = 15,070) at a 10:1 ratio. Our sample was 46% White, 17% Hispanic, 16% Asian, 7% Black, and 14% other race/ethnicity. We compared health diagnoses (a) between autistic and non-autistic adults within strata of race/ethnicity and (b) across race/ethnicity within strata of autistic and non-autistic adults. Lastly, we examined the interaction between autism and race/ethnicity on both multiplicative and additive scales.

Results: Autistic adults were more likely to be diagnosed with most medical and psychiatric conditions compared with their non-autistic counterparts of the same race/ethnicity. Among autistic adults, Black, Hispanic, and Asian adults were less likely to be diagnosed with psychiatric conditions and Black and Hispanic autistic adults were more likely to be diagnosed with obesity than their White counterparts. In interaction models, we found that adults who were Black and autistic were disproportionately less likely to be diagnosed with psychiatric conditions and autoimmune disease and more likely to be diagnosed with hypertension than expected.

Conclusion: Health vulnerabilities may be compounded at the intersection of autism and race/ethnicity. Future research should continue to apply an intersectional lens toward understanding and addressing these disparities. Our findings likely underestimate the health disparities that exist in uninsured autistic adults and those living in other parts of the United States.